Sixteen months ago, comparative effectiveness research (CER) began its rapid rise, when the American Recovery and Reinvestment Act of 2009 allocated $1.1 billion for CER. This progress report summarizes how the recipients of the funds—the National Institutes of Health, Agency for Healthcare Research and Quality, and Office of the Secretary of the U.S. Department of Health and Human Services—are spending the $1.1 billion, how the Institute of Medicine priority topics have fared in the agencies' funding programs, and the developing plans for a national CER program. As the United States works to absorb 32 million currently uninsured people into the health care system while simultaneously improving the quality of care and slowing cost increases, CER will increasingly be a necessary component of this change.